SECT.  XXXI.  Of the Structure of Man’s Body.

The body is made of clay; but let us admire the Hand that framed and polished it.  The Artificer’s Seal is stamped upon His work.  He seems to have delighted in making a masterpiece with so vile a matter.  Let us cast our eyes upon that body, in which the bones sustain the flesh that covers them.  The nerves that are extended in it make up all its strength; and the muscles with which the sinews weave themselves, either by swelling or extending themselves, perform the most exact and regular motions.  The bones are divided at certain distances, but they have joints, whereby they are set one within another, and are tied by nerves and tendons.  Cicero admires, with reason, the excellent art with which the bones are knit together.  For what is more supple for all various motions?  And, on the other hand, what is more firm and durable?  Even after a body is dead, and its parts are separated by corruption, we find that these joints and ligaments can hardly be destroyed.  Thus this human machine or frame is either straight or crooked, stiff or supple, as we please.  From the brain, which is the source of all the nerves, spring the spirits, which are so subtle that they escape the sight; and nevertheless so real, and of so great activity and force, that they perform all the motions of the machine, and make up all in strength.  These spirits are in an instant conveyed to the very extremities of the members.  Sometimes they flow gently and regularly, sometimes they move with impetuosity, as occasion requires; and they vary ad infinitum the postures, gestures, and other actions of the body.